How to create dynamically controllers function name in codeigniter

[eluser]beeLoop[/eluser]
With reference to your thread,

http://your.app/display/home
http://your.app/display/news
http://your.app/display/portfolio

But i don't need like this, it would be like

http://your.app/user_name1
http://your.app/user_name2

So Let me rephrase my query like:
So , what are the possible ways to create dynamically controllers in codeigniter, not controller functions.